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[partition] minor changes and added robustness test
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@barendgehrels
barendgehrels committed May 8, 2023
1 parent 03489ca commit a8bd9a0
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Showing 3 changed files with 447 additions and 75 deletions.
121 changes: 62 additions & 59 deletions include/boost/geometry/algorithms/detail/partition.hpp
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Original file line number Diff line number Diff line change
Expand Up @@ -52,20 +52,39 @@ struct divide_interval<T, true>
{
static inline T apply(T const& mi, T const& ma)
{
// avoid overflow
// Avoid overflow
return mi / 2 + ma / 2 + (mi % 2 + ma % 2) / 2;
}
};

template <int Dimension, typename Box>
struct visit_no_policy
{
template <typename Box>
static inline void apply(Box const&, std::size_t )
{}
};

struct include_all_policy
{
template <typename Item>
static inline bool apply(Item const&)
{
return true;
}
};


template <std::size_t Dimension, typename Box>
inline void divide_box(Box const& box, Box& lower_box, Box& upper_box)
{
typedef typename coordinate_type<Box>::type ctype;
using coor_t = typename coordinate_type<Box>::type;

// Divide input box into two parts, e.g. left/right
ctype mid = divide_interval<ctype>::apply(
geometry::get<min_corner, Dimension>(box),
geometry::get<max_corner, Dimension>(box));
// Divide input box into two halves
// either left/right (Dimension 0)
// or top/bottom (Dimension 1)
coor_t const mid
= divide_interval<coor_t>::apply(geometry::get<min_corner, Dimension>(box),
geometry::get<max_corner, Dimension>(box));

lower_box = box;
upper_box = box;
Expand Down Expand Up @@ -143,7 +162,7 @@ inline bool handle_one(IteratorVector const& input, VisitPolicy& visitor)
{
if (! visitor.apply(**it1, **it2))
{
return false; // interrupt
return false; // Bail out if visitor returns false
}
}
}
Expand Down Expand Up @@ -174,7 +193,7 @@ inline bool handle_two(IteratorVector1 const& input1,
{
if (! visitor.apply(*it1, *it2))
{
return false; // interrupt
return false; // Bail out if visitor returns false
}
}
}
Expand Down Expand Up @@ -215,11 +234,11 @@ inline bool recurse_ok(IteratorVector1 const& input1,
}


template <int Dimension, typename Box>
template <std::size_t Dimension, typename Box>
class partition_two_ranges;


template <int Dimension, typename Box>
template <std::size_t Dimension, typename Box>
class partition_one_range
{
template <typename IteratorVector, typename ExpandPolicy>
Expand Down Expand Up @@ -328,10 +347,10 @@ public :
if (! boost::empty(exceeding))
{
// Get the box of exceeding-only
Box exceeding_box = get_new_box(exceeding, expand_policy);
Box const exceeding_box = get_new_box(exceeding, expand_policy);

// Recursively do exceeding elements only, in next dimension they
// will probably be less exceeding within the new box
// Recursively do exceeding elements only, in next dimension they
// will probably be less exceeding within the new box
if (! (next_level(exceeding_box, exceeding, level, min_elements,
visitor, expand_policy, overlaps_policy, box_policy)
// Switch to two forward ranges, combine exceeding with
Expand All @@ -341,7 +360,7 @@ public :
&& next_level2(exceeding_box, exceeding, upper, level, min_elements,
visitor, expand_policy, overlaps_policy, box_policy)) )
{
return false; // interrupt
return false; // Bail out if visitor returns false
}
}

Expand All @@ -355,7 +374,7 @@ public :

template
<
int Dimension,
std::size_t Dimension,
typename Box
>
class partition_two_ranges
Expand Down Expand Up @@ -459,20 +478,20 @@ public :

if (recurse_ok(exceeding1, exceeding2, min_elements, level))
{
Box exceeding_box = get_new_box(exceeding1, exceeding2,
expand_policy1, expand_policy2);
Box const exceeding_box = get_new_box(exceeding1, exceeding2,
expand_policy1, expand_policy2);
if (! next_level(exceeding_box, exceeding1, exceeding2, level,
min_elements, visitor, expand_policy1, overlaps_policy1,
expand_policy2, overlaps_policy2, box_policy))
{
return false; // interrupt
return false; // Bail out if visitor returns false
}
}
else
{
if (! handle_two(exceeding1, exceeding2, visitor))
{
return false; // interrupt
return false; // Bail out if visitor returns false
}
}

Expand All @@ -482,23 +501,23 @@ public :
// the same combinations again and again)
if (recurse_ok(lower2, upper2, exceeding1, min_elements, level))
{
Box exceeding_box = get_new_box(exceeding1, expand_policy1);
Box const exceeding_box = get_new_box(exceeding1, expand_policy1);
if (! (next_level(exceeding_box, exceeding1, lower2, level,
min_elements, visitor, expand_policy1, overlaps_policy1,
expand_policy2, overlaps_policy2, box_policy)
&& next_level(exceeding_box, exceeding1, upper2, level,
min_elements, visitor, expand_policy1, overlaps_policy1,
expand_policy2, overlaps_policy2, box_policy)) )
{
return false; // interrupt
return false; // Bail out if visitor returns false
}
}
else
{
if (! (handle_two(exceeding1, lower2, visitor)
&& handle_two(exceeding1, upper2, visitor)) )
{
return false; // interrupt
return false; // Bail out if visitor returns false
}
}
}
Expand All @@ -508,23 +527,23 @@ public :
// All exceeding from 2 with lower and upper of 1:
if (recurse_ok(lower1, upper1, exceeding2, min_elements, level))
{
Box exceeding_box = get_new_box(exceeding2, expand_policy2);
Box const exceeding_box = get_new_box(exceeding2, expand_policy2);
if (! (next_level(exceeding_box, lower1, exceeding2, level,
min_elements, visitor, expand_policy1, overlaps_policy1,
expand_policy2, overlaps_policy2, box_policy)
&& next_level(exceeding_box, upper1, exceeding2, level,
min_elements, visitor, expand_policy1, overlaps_policy1,
expand_policy2, overlaps_policy2, box_policy)) )
{
return false; // interrupt
return false; // Bail out if visitor returns false
}
}
else
{
if (! (handle_two(lower1, exceeding2, visitor)
&& handle_two(upper1, exceeding2, visitor)) )
{
return false; // interrupt
return false; // Bail out if visitor returns false
}
}
}
Expand All @@ -535,14 +554,14 @@ public :
min_elements, visitor, expand_policy1, overlaps_policy1,
expand_policy2, overlaps_policy2, box_policy) )
{
return false; // interrupt
return false; // Bail out if visitor returns false
}
}
else
{
if (! handle_two(lower1, lower2, visitor))
{
return false; // interrupt
return false; // Bail out if visitor returns false
}
}

Expand All @@ -552,37 +571,21 @@ public :
min_elements, visitor, expand_policy1, overlaps_policy1,
expand_policy2, overlaps_policy2, box_policy) )
{
return false; // interrupt
return false; // Bail out if visitor returns false
}
}
else
{
if (! handle_two(upper1, upper2, visitor))
{
return false; // interrupt
return false; // Bail out if visitor returns false
}
}

return true;
}
};

struct visit_no_policy
{
template <typename Box>
static inline void apply(Box const&, std::size_t )
{}
};

struct include_all_policy
{
template <typename Item>
static inline bool apply(Item const&)
{
return true;
}
};


}} // namespace detail::partition

Expand Down Expand Up @@ -667,14 +670,14 @@ class partition
std::size_t min_elements,
VisitBoxPolicy box_visitor)
{
typedef typename boost::range_iterator
using iterator_t = typename boost::range_iterator
<
ForwardRange const
>::type iterator_type;
>::type;

if (std::size_t(boost::size(forward_range)) > min_elements)
{
std::vector<iterator_type> iterator_vector;
std::vector<iterator_t> iterator_vector;
Box total;
assign_inverse(total);
expand_to_range<IncludePolicy1>(forward_range, total,
Expand All @@ -688,16 +691,16 @@ class partition
}
else
{
for(auto it1 = boost::begin(forward_range);
for (auto it1 = boost::begin(forward_range);
it1 != boost::end(forward_range);
++it1)
{
auto it2 = it1;
for(++it2; it2 != boost::end(forward_range); ++it2)
for (++it2; it2 != boost::end(forward_range); ++it2)
{
if (! visitor.apply(*it1, *it2))
{
return false; // interrupt
return false; // Bail out if visitor returns false
}
}
}
Expand Down Expand Up @@ -793,21 +796,21 @@ class partition
std::size_t min_elements,
VisitBoxPolicy box_visitor)
{
typedef typename boost::range_iterator
using iterator1_t = typename boost::range_iterator
<
ForwardRange1 const
>::type iterator_type1;
>::type;

typedef typename boost::range_iterator
using iterator2_t = typename boost::range_iterator
<
ForwardRange2 const
>::type iterator_type2;
>::type;

if (std::size_t(boost::size(forward_range1)) > min_elements
&& std::size_t(boost::size(forward_range2)) > min_elements)
{
std::vector<iterator_type1> iterator_vector1;
std::vector<iterator_type2> iterator_vector2;
std::vector<iterator1_t> iterator_vector1;
std::vector<iterator2_t> iterator_vector2;
Box total;
assign_inverse(total);
expand_to_range<IncludePolicy1>(forward_range1, total,
Expand Down Expand Up @@ -835,7 +838,7 @@ class partition
{
if (! visitor.apply(*it1, *it2))
{
return false; // interrupt
return false; // Bail out if visitor returns false
}
}
}
Expand Down
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